Data storage systems commonly employ continuous data protection (CDP), also known as “continuous replication,” for protecting the data they store. Continuous replication operates on storage volumes using Fibre Channel or iSCSI (Internet Small Computer System Interface), for example, to replicate data writes performed on storage volumes at a source to replicas of the storage volumes maintained at a destination. Continuous replication generally allows administrators to perform point-in-time recovery of a volume to a previous state with fine granularity.
A well-known solution for continuous data protection is the RecoverPoint system available from EMC Corporation of Hopkinton, Mass. RecoverPoint systems include a replication splitter and one or more local appliances, both at a source data storage system and at a destination data storage system. As the source processes IO (Input/Output) requests that specify data to be written to a particular volume, the replication splitter at the source intercepts the IO requests and sends them to the local appliance. The appliance at the source communicates with the appliance at the destination, and the two appliances orchestrate the storage of the data specified in the IO requests at the destination. In this manner, the destination is made to store a current, or nearly current, replica of the volume. In addition, journaling of changes made to the replica allow one to achieve point-in-time recovery in the event of a failure at the source or as otherwise desired.